This invention relates to disposable diapers. More particularly, this invention relates to disposable diapers adapted to be secured in place by adhesive tabs.
Disposable diapers provide substantial advantages in convenience over diapers intended to be laundered and reused, particularly when they are used away from home. In recent years, many different disposable diapers have been proposed and some have been successful in the marketplace. Typical disposable diaper structures comprise a moisture-retaining layer of high liquid-holding capacity and a moisture-impervious backing sheet, generally made of a plastic film such as polyethylene film or the like. Typical disposable diaper structures are shown in U.S. Pat. No. 3,612,055 to Mesek et al. and in U.S. Pat. No. Re. 26,151 to Duncan et al.
As may be seen from the above-cited patents, it is desirable to obviate the problems that are inherent in closure systems which utilize extraneous fasteners such as safety pins, snaps and zippers. To this end adhesive closure systems have presented acceptable solutions.
One of the most convenient adhesive systems that has been developed to date is the system, shown in the above-cited patents, in which adhesive tabs are adhered to the backing sheet extending outwardly from opposite sides of the diaper at one end thereof, and in which the exposed areas of the adhesive strips are provided with readily separable cover strips which protect the exposed areas until ready for use. However, disposable diapers using an adhesive closure system of this general type have the disadvantage that the consumer has to dispose of the cover strips when they are separated from the adhesive tabs. This is an inconvenience to the consumer who is placing the diaper on a baby at about the same time.
An illustrative prior art adhesive system having cover strips permanently attached to the diaper is disclosed in U.S. Pat. No. 3,646,937 to Gellert. The Gellert arrangement has the disadvantage of having a release film permanently anchored to the inside surface of the diaper, where it can possibly come into contact with a baby's tender skin. Additional disadvantages are the complexities and expense which are added to the manufacturing process by requiring each adhesive closure to be manipulated on the front side, around the edge, and on to the back side of the diaper, instead of handling the adhesive closure on one side only.
Another prior art patent, U.S. Pat. No. 3,049,124 to Thompson, avoids the use of cover strips by utilizing tie strings which extend transversely across the entire width of the diaper. In the Thompson arrangement, however, the tie strings are part of a rubber panty into which disposable diaper is positioned, and the tie strings are positioned on the inside surface of the panty where it will contact a baby's skin. Additional disadvantages include the need for at least two strings extending transversely across the diaper because of the requirement of tying one string to an opposite string.
In U.S. Pat. No. 3,847,702 to Jones, a pair of non-extensible reinforcing waist bands are secured to a relatively thin fluid impermeable backing sheet of a diaper. The reinforcing waistbands extend transversely across the backing sheet at each end of the diaper and are intended for adhesive securement to each other. Both ends of at least one of the bands have adhesive coated areas which are adhesively bonded to the other band at the opposite end of the diaper. Two such bands are required because the fluid impermeable backing sheet is only 0.0003-0.0005 inch thick and would cold stretch on tensile loading if the adhesive areas at the ends of one of the waistbands were bonded directly to the backing sheet.